Dental instrument.



R. T. URNLEY.

DENTAL INSTRUMENT. APPLICATION FILED APE. 14, 190s.

, 907,003. Patented nec. 15,1908.

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RICHARD TOLBERT BURNLEY, OF ATLANTA, GEORGIA.

DENTAL INSTRUMENT.

Specification of Letters Patent.

Application led April 14, 1908.

Patentedrnec. 15, 190s.

seria No. 426,991.

To all whom it may concern.'

Be it known that I, RICHARD TOLBERT BUENLEY, a citizen of the UnitedStates, residing at Atlanta, in the county of Fulton and tate ofGeorgia., have invented certain new and useful Im rovements in DentalInstruments, of whic the following is a specification.

This invention relates to improvements in tools designed primarily foroperating in connection with broaches and the like, by hand.

The rear teeth of a patient are extremely difficult to operate upon byreason of the fact that with tools now 1n use, it is necessary to insertthe fingers in the mouth to manipulate them, which is awkward andfrequently hides from view the articular part to be treated. This isespecially true in removing a nerve from a rear tooth.

Accordin to my invention, I provide an instrument aving the parts soarranged that the broach may be operated by means wholly outside` themouth, which enables the operator to have a full view of the particularpart being treated. The broach is angularly disposed, and may beinserted in the root canal, and revolved to grip the nerve and remove itfrom the tooth.

The fundamental feature of the invention is to cpnstruct and arrange theparts in simple, yet durable form, whereby a tool is rendered practicaland eflicient.

The invention also possesses other advanta es, which will be hereinafterdescribed.

n the drawings: Figure 1 is a perspective view of the tool. Fig. 2 is avert1oal central section. Fig. 3 is a similar view of one end, on anenlarged scale. Fi 4 is a detail perspective view of the chuc. Fig. 5 isa detail cross section taken through the tubular handle.

The numeral 1, indicates a tubular handle, which receives ashaft 2,formed at its outer end with a finger iece 3, and provided at itsopposite end witli a small pinion 4. The ends of the handle 1, fitagainst the finger piece 3, and the pinion 4, respectively, to retainthe shaft in pro er relation, and thereby prevent its bein isplaced. Thepinion is secured to the s aft in any appro riate manner, and asl itwears may be read y replaced.

The handle 1, is threaded at 5, adjacent the pinion 4, and receives thethreaded end of a coupling member 6. The opposite end of the coupling isformed with an angular'extension 7, the bottom of which is formed with asemi-spherical seat 8, and its outer end is interiorly threaded at 9.

Fitting in the angular extension 7, is a chuck member 10, formed at itslower end with a semi-spherical base 11, which fits in the semi-sherical seat 8. The chuck is formed wit a beveled pinion 12, designed tomesh with the pinion 4, and extending beyond the pinion is a threadedsplit extension 13. The chuck is formed with a central opening 14,throughout its entire length to receive the end of a broach or the like.A threaded collar 15, engages the threaded portion 9, of the angularportion of the coupling, and bears on the beveled pinion 12, to hold thechuck in position in said coupling. A threaded nut 14a, engages thethreaded Split extension 13, to bind the broach in fixed position tocause it to turn with the chuck, when the finger piece is operated.

By reason of the chuck having an opening throughout its entire length,the yoperative distance between the end of the broach, and the nut 14a,may be altered, which quite freuently is required, depending entirely ont e nature ofthe treatment and the location of the tooth.

On each side of the tubular handle, is formed a groove 20, to receivebraces 21-21, hinged at 22, and retained in the grooves when not in useby a movable ring 23. This construction affords a right or left handoutwardly extending member, to steady the tool when operating the fingerpiece. By reason of the angular disposition of the braces, it enablesthe operator to obtain the desired leverage, and at the same time willallow of the hand holding the tool being out of the way of the front ofthe mouth.

In operation, the end of the tool is inserted in the mouth of theatient, and the broach is located in the cana of the particular tooth tobe treated. The finger piece is rotated, which, through the gearconnection, rotates the broach and gradually withdraws the nerve.Obviously the operator has full view, which makes the tool advantageouswhen treating a rear tooth. Furthermore, by the angular disposition ofthe chuck, and the means providedfor adjusting the broach make the tooloperable to varying conditions so frequently occurring when fillingteeth.

By constructing the chuck of one piece as described, I reduce theliability of loss of parts, and consequent delay, to a minimum,

and at the same time produce a simple and compact structure susceptibleof quick attaching and detaching of the broach when necessary. Thissemi-spherical end of the chuck and its seat, serve to form an abutmentfor the chuck when pressure is applied to it, and serves also to reducefriction between the gears. For instance, if the chuck did not abutagainst the base of the eXtension, when pressure is applied to the saidchuck, the gears would be forced together, consequently creating a greatdeal of friction between the gears, and thereby necessitating, a greatereffort to turn the handle.

What I claim is:

l. In a dental instrument, a tubular handle, a shaft extending throughthe handle and provided at one end with a finger piece, a pinion securedto the opposite end of the shaft, the pinion and finger piece bearingrespectively against the inner and outer ends of the tubular handle, anangular tubular eX- tension fitted on the tubular handle and formed atan end with a concave seat internally threaded at its opposite end, achuck formed with an opening having a convex head at one end to engagethe concave seat in the extension, the opposite end of the chuck beingreduced and split a pinion fast on the chuck which engages the pinion onthe shaft, a threaded nut engaging the internally threaded portion ofthe extension and engaging the pinion on the chuck to hold said pinionin engagement with the pinion on the shaft, and retain the chuck in theextension, and means cooperating with the split end of thechuck togholda tool.

2. In a dental instrument, a tubular handle, a shaft mounted in thehandle and provided on one end with a finger piece which abuts againstone end of the tubular hanformed at its free end with a split eXteriorlythreaded extension and formed with a centrally disposed openingextending throughout its entire length, a pinion intermediate theextension and the base of the chuck, said pinion engaging the pinion onthe shaft, and a threaded nut engaging the threaded portion of theangular extension and above the pinion to retain the chuck in osition.

3. In a dental instrument, t e combination with a tubular handle, ashaft mounted in the tubular handle, a chuck, gears between the chuckand the handle, a brace on the tubular handle to steady the instrument,and a device to lock the brace close to the handle.

4. In a dental instrument, the combination with a tubular handle formedwith grooves, a shaft mounted therein, a finger piece on the shaft, achuck, gears between the chuck and the shaft, braces hinged to thehandle and normally seated in the grooves, and a locking device to holdthe braces in the grooves when not in use.

5. In a dental instrument, the combina tion with a handle and a chuckfor holding a tool, and a hinged brace on the handle to steady theinstrument.

In testimony whereof I afliX mysignature in presence of two witnesses. y

RICHARD TOLBERT BURNLEY.

Witnesses:

W. N. WooDsoN, JNO. IMIRIE.

